Method of producing lubricating oils



Sept. 12,` 1939.

H. GOETHEL EF AL METHOD 0F PRODUCING LUBRICATING OILS Filed Aug. 18, 1936 Patented Sept. 12, 19395 UNITED STATES 'PATENT ori-ice 2,172,441 f f METnon or Pnoromcgnva Lnnmoarnva Herbert Goethel, l rich Tramm,

Duisburg-Hamborn, and Heinf' Cberhausen-Holten,

,Application August 1s, 193s, Germany August Germany .Serial No. @6.553%

6 Claims. (Cl. li-l Our inventionrelates to lubricating oils, and more particularly to an improved method of articialiy producing the same.

It is an object of our invention to produce at different temperatures.

It is still a further object of our 1o provide, in the production of lubricating oils, for

aluminium chloride 1n the conversion of Successive charges of the starting products.

It is a particular l improve the general production of lubricating oils.

ln the production of lubricating oils it has a1- ready been suggested to condense petroleum distillates having a high content of unsaturated hy- It has further been suggested to employ cracking products as starting material. Thus for ex- 36 In order to obtain a satisfactory yield of lubriwhich are solid at normal temperature. On the contrary, lower boiling hydrocarbon mixtures can be used, including all constituents boiling above U C. According to ,the present invention the frac- 50 tions boiling above 150 C. of the hydrocarbon `5 'merization of the mixtures obtained in the crackeconomy of. the artificialv a considerable saving of con- In this manner a of the method of obtained.

According to the present invention we may for cracking the above identified fractions of the` 'liquid hydrocarbons recovered from carbon moneither totally or partly, e. g.,

chloride or some other condensing agent. Byl such condensation a'nd polymerization we obtain viscous oils, which display extraordinarily favorable lubricating properties. The products thus obtained are distinguished by a quite extraordinarily low dependency of their viscosity from the temperature, i. e., an extraordinarily favorable value of the viscosity apex, and on the other hand by so low a, solidifying point, that the synthetic lubricating oils thus produced will act as lubricants even at low outside or operating temperatures. We found that when starting from the constituents of the cracking products boiling up to 200 C., particularly useful lubricating oils were obtained, which are distinguished primarily 1 by their remarkably low solidifying point. Thus, for example, lubricating oils were obtained, which display a value of the viscosity apexcalculated according to Ubbelohde (cf. Zur Viskosimetrle, published in-1936 by S. Hirzel, Leipzig, Germany) of from 1.75 to 1.9, an absolute viscosity of from 12 to 22 Engler at 50 C., corresponding to 419- ing to the invention, are not in point of from products 750 Saybolt seconds at 122 E. and a solidifying -32 C. to 20"` C. Particularly remarkable is also the extraordinarily high tensile strength of the oil film heavily leaded in bearings. l

This property together with their low solidifying point renders the new lubricating oil obtained according to the present invention particularly suitable for many purposes. Also their tendency of resinification and carbon formation /dur-ing the coklng of the lubricating oils obtained accordany respect less favorable than those of the very best lubricating `ils now on the market.

The amount'of condensation agents, which are required in each individual operation, for the polymerization and condensation of the cracking obtained in the manner Vabove referred to, lies within the usual limits. It has, however, been found, that the starting material employed according to the present invention is particularly suited for a repeated use of the condensing agent in the condensation of new charges of hydrocarbons. Therefore the layer containing the condensing agent which remains over when separating the products of conversion is used repeatedly for like reactions of condensation. Preferably, whenever the already -used condensing agent is put to renewed use, the temperature nf condensation is increased correspondingly. This step results in a considerable saving of the condensing agentv required in the execution of the method according to the invention; no detrimental eiect of a repeated use of the condensing agent on the quality of the lubricating oils has been observed. Thus, for example, the catalyst used in the first charge was re-used in the condensation reaction eight times, each' time with a new charge, without being exhausted after such repeateduse. While, according to the methods hitherto known of producing synthetic lubricating oils, one part aluminper 6 to 10 parts of the present lum chloride vwas required the lubricating oil recovered, with method of producing lubricating oils the amount ofl catalyst required is reduced to at least one tenth.

This saving of condensing agent could by no means be expected. On the contrary, one was rat-her inclined to fear that just the hydrocarbon mixtures obtained in the cracking process, owing to -their content of constituents tending toward resinificatlon, would render the catalystinoperative within a very Ishort time.

` ordinarily valuable precipitating In the practice of the present invention the contrary has been esv tablished.4

Example 1 A gas mixture containing one part by volume of carbon `monoxide and two parts hydrogen, which had been freed from sulfur compounds, is passed at about 180 C. and under normal pressure in contact with a cobalt catalyst. After cooling, liquid hydrocarbons separate out from the reaction gas obtained, which is now passed over active carbon in order to extract therefrom the lower boiling benzines, which have remained in the gaseous phase. The constituents boiling above 150 C. of the liquid hydrocarbons thus obtained are cracked at a pressure of 8 atm. and at a temperature of 493 C'. From the cracking products thus obtained a fraction distilling up to 200 C. is separated, which at 20. C. has a density of 0.702. This distillate is reacted 'with 5% aluminium chloride in an agitator, while cooling it at 20 C. during 48 hours. The reaction product freed from the contact mass by washing with water is distilled in vacuo, after having been dried and treated with fullers'earth. There are obtained per 100 parts of the cracking products used 53 parts of oil, from which, after. the separation of refrigerator oil, 43 parts of an extralubricating oil possessing the above-mentioned properties are obtained.

The cobalt catalyst mentioned above may for instance consist of cobalt-thorium-oxide deposited on kieselguhr and obtained by adding kieselguhr to a solution of a cobalt-thorium-salt and this solution with an aqueous solution of carbonate of soda. The precipitate obtained is filtered from the solution and dried and, before the operation, reduced with hydrogen at 30G-350 C. The catalyst thus prepared may for instance consist of 37.3 percent cobalt, 6.7 per cent thorium oxide and 56.0 per cent kieselguhr.

Instead of a cobalt catalyst a nickel catalyst may be used which may for instance be obtained by suspending purified kieselguhr in water, adding to the suspension a mixture of nickel nitrate and thorium nitrate, which contains 12 per c'ent thorium, calculated-as metal, in relation to the nickel, precipitating with a soda solution, and sucking off the precipitate thus obtained, washing and drying it and subsequently reducing this catalyst at 350 C. in a current of hydrogen. Any other catalyst known to promote the reduction of a mixture of carbon monoxide and hydrogen under the formation of hydrocarbons may be used instead of the catalysts specified above.

Example 2 hpolymerized during 24 hours in the presence of 5 parts of fresh aluminium chloride at 20 C. in an agitator. The product of reaction is separated from the liquid layer containing the catalyst, which layer is again used in the conversion of a similar amount of freshly charged cracking products. 'I'he materials are allowed to react for 24 hours at a temperature of 55. The oils recovered are separated in a similar manner from the liquid layer containing the catalyst. This catalyst layer is vthen caused again to react with new cracking products for 24 hours at 90 C. In a similar manner the process is repeated at C., at C., and at 170 C., always one and the same quantity of catalyst or condensing agent being used. 'I'he total process results in a yield of lubricating oils amounting to 52% of the 600 parts of cracking product used, the following 'amounts being recovered from the individual charges:

From the rst charge 42 parts;

From the second charge 52 parts;

From the third charge 55 parts;

' From the fourth charge 58 parts;

From the iifth charge 57 parts, and

From the sixth charge 50 parts. I

Theoils thus produced possess the same extraordinarily favorable characteristics, which were referred to above in detail.

The drawing illustrates the mode of operation as explained with reference to the examples. I is a reaction oven containing a 'suitable catalyst for the conversion of the C0 and Hz introduced into this oven. 'I'he products of reaction, after being cooled in the cooler 2, are introduced into the separator 3, from which the gases may escape through, pipe and valve 4, while lower boiling benzines may be extracted for instance with activated carbon. The liquid hydrocarbons thus obtained which boil above C., are led through .the pipes 6' and 9 to thepump I0, which forces them into the cracking oven Il. The separation of the constituents boiling above 150 C. may also be carried out in the still 5; the undesired products are allowed to escape through pipe 8 at 1, while the constituents boiling above 150 C. flow through pipe 26 to the pump I0. The gaseous cracked products leaving-the oven II are introduced into the condenser I2, from which those parts which remain gaseous,escape at 21, while the condensed parts are caused to flow either through pipes I3 and I8 to the polymerizing vessel I9 or through pipe 25 to the still I 5 in which they are distilled. 'Ihe hydrocarbon materials boiling above 200 or 230 C.are Withdrawn at I 6, while the cracking products which boil up to 200 or 230 C., are condensed in the condenser I1 and pass in liquid state through pipes I4 and I8 into the polymerizing vessel I9 which is provided with the feed pipe 20 for the catalyst. The polymer-ized products are withdrawn through pipe 2| and are led t'o a purier 22 from. which the undesired products are withdrawn at 23, while the lubricating oil formed enters the tank 24.

Numerous advantages are obtained with the method of producing. lubricating oils according to the present invention. I'he percentage of valuable lubricating oils recovered from a predey from conversion containing a termined quantity of cracking products is greatly increased. 'Ihe lubricating oils obtained possess a remarkably low solidiiying point and quite particularly show a great constancy of the viscosity at varying temperatures. such as aluminium chloride can be reused a great charges of cracking products. summarizing the above advantages of the new method, the economy of the production of valuable lubricating oils is greatly enhanced.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof. l

We claim:

1. The method of producing lubricating oils products o1' the hydrogenation of carbon monoxide, comprising the' steps of subjecting the fractions, which are liquid at room temperature, boil above150 C. and comprise a substantial portion boiling directly above 150 C Y of hydrocarbon mixtures obtained in the catalytic conversion of mixtures of carbon monoxide and hydrogen, `to a cracking treatment such as to yield a mixture of hydrocarbons having a high content of unsaturated lwdrocarbons, and subsequently polymerizing said last-named mixture inthe presence of a polymerizing agent or catalyst containing a metal halide.

2. 'I'he method of producing lubricating oils from conversion products of the hydrogenation of carbon monoxide', comprising the steps of sub- Jecting the fractions which are liquid at room temperature, boil above 150 C. and comprise a `substantial portion boiling directly above 150 C., of hydrocarbon mixtures obtained in the catalytic conversion of mixtures of carbon monoxide and hydrogen, to a cracking treatment at temperatures ranging between about 450 and 550 C. and at a pressure ranging between about 8 and 15 atmospheres, and subsequently polymerizing, in the presence of a polymerizing agent or catalyst metal halide, the mixtures obtained in this treatment of hydrocarbons rich in unsaturated compounds.

3. The method of 6. 'I'he method of claim 2, wherein the polymerizing agents used in the polymerization of HERBERT GOETHEL. HEINRICH TRAMM.

The condensing agent' number of times in the conversion of subsequent 

